Efficacy and field safety of ilunocitinib for the control of atopic dermatitis in client-owned dogs: A multicentre, double-masked, randomised, placebo-controlled clinical trial.

Abstract

BACKGROUND: Inhibition of the Janus kinase (JAK) pathway is a well-established option for canine atopic dermatitis (cAD). OBJECTIVE: To evaluate the efficacy and safety of ilunocitinib, a novel JAK inhibitor for the control of pruritus and skin lesions in client-owned dogs with cAD. ANIMALS: Two hundred sixty-eight dogs at 25 veterinary clinics. MATERIALS AND METHODS: In this randomised, double-masked, clinical trial, dogs received either ilunocitinib (n&#x2009;=&#x2009;181; 0.6-0.8&#x2009;mg/kg) or placebo (n&#x2009;=&#x2009;87; 0.0&#x2009;mg/kg) tablets once daily for 112&#x2009;days. Pruritus was assessed by owners using a pruritus Visual Analog Scale (PVAS), while skin lesions were assessed by Investigators using the cAD Extent and Severity Index, 4th iteration (CADESI-04). Treatment success was defined as &#x2265;50% reduction from baseline PVAS or CADESI-04 score on Day (D)28. Proportions of dogs achieving clinical remission from pruritus (PVAS&#x2009;<&#x2009;2) or skin lesions (CADESI-04&#x2009;<&#x2009;10) also were assessed. RESULTS: At D28, 83% of ilunocitinib-treated dogs achieved treatment success compared to 31% of placebo-treated dogs (p&#x2009;<&#x2009;0.001). A significantly higher proportion of ilunocitinib-treated dogs achieved &#x2265;50% reduction in CADESI-04 scores at all time points (p&#x2009;<&#x2009;0.001). The proportion of dogs achieving clinical remission PVAS or CADESI-04 scores was significantly higher in the ilunocitinib group starting on D7 and D14, respectively (p&#x2009;<&#x2009;0.05). The 112-day ilunocitinib treatment was well tolerated. CONCLUSIONS AND CLINICAL RELEVANCE: Once daily ilunocitinib was well-tolerated and effective at rapidly reducing pruritus and resolving cAD-associated skin lesions. Clinical remission was achieved by two-thirds of dogs after 4&#x2009;months of treatment. Ilunocitinib is safe and effective for managing clinical signs associated with cAD.